Optimisation des query dans le cas d'un @joinColumn

Salut,

Considerons deux Tables associées à l'aide d'un @joinColumn:

Code:

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@Entity
public class Provider implements java.io.Serializable,{
    @Id
    @GeneratedValue
    protected int id;
    protected String status;
 
    @OneToOne(cascade=CascadeType.ALL)
    @JoinColumn(name="fk_contact")
    protected Contact contact;
...
}

Code:

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@Entity
public class Contact implements java.io.Serializable{
    @Id
    @GeneratedValue
    protected int id;
    protected String address;
    protected String locale;
...
}

Lors de select suivant

Code:

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entityManager.createQuery("select c from Provider C order by c.name").getResultList();

j'obtient en SQl 1 select Provider + 1 select Contact par objet Provider

Code:

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Hibernate: select provider0_.id as id10_, provider0_.fk_contact as fk5_10_, provider0_.name as name10_, provider0_.pref_logo_size as pref3_10_, provid
er0_.status as status10_ from Provider provider0_ order by provider0_.name
Hibernate: select contact0_.id as id4_0_, contact0_.address as address4_0_, contact0_.email as email4_0_, contact0_.given_name as given4_4_0_, contact
0_.locale as locale4_0_, contact0_.sur_name as sur6_4_0_, contact0_.telephone as telephone4_0_ from Contact contact0_ where contact0_.id=?
Hibernate: select contact0_.id as id4_0_, contact0_.address as address4_0_, contact0_.email as email4_0_, contact0_.given_name as given4_4_0_, contact
0_.locale as locale4_0_, contact0_.sur_name as sur6_4_0_, contact0_.telephone as telephone4_0_ from Contact contact0_ where contact0_.id=?
Hibernate: select contact0_.id as id4_0_, contact0_.address as address4_0_, contact0_.email as email4_0_, contact0_.given_name as given4_4_0_, contact
0_.locale as locale4_0_, contact0_.sur_name as sur6_4_0_, contact0_.telephone as telephone4_0_ from Contact contact0_ where contact0_.id=?
Hibernate: select contact0_.id as id4_0_, contact0_.address as address4_0_, contact0_.email as email4_0_, contact0_.given_name as given4_4_0_, contact
0_.locale as locale4_0_, contact0_.sur_name as sur6_4_0_, contact0_.telephone as telephone4_0_ from Contact contact0_ where contact0_.id=?

Ne peut-on pas améliorer cela?

Merci pour vos réponse!

Salut,

Normalement Hibernate peut charger 2 objets en un select à l'aide d'une jointure.

Essaye de rajouter à ton mapping : fetch=join & lazy=false.

Plutôt que de le faire sur le mapping, il est préférable de le faire dans la requête:
Code:

1 2 select p from Provider p inner join fetch p.contact order by p.name

Merci beaucoup pour votre aide!

J'ai pris la solution de fr1man qui marche très bien!